Apparatus and method for molding meat patties

ABSTRACT

A molding apparatus and method are provided for forming patties from an agglomerable edible material such as meat. The apparatus includes a turret which rotates between a feed station where the edible material is fed upwardly under pressure into one of a plurality of mold cavities and a discharge station where each formed patty is ejected by a piston. An improved sealing means is provided for effecting sealing engagement of a feed spout assembly with the bottom surface of the rotating turret. An improved cut-off band is also provided for separating the formed patties from the turret at the discharge station. Reciprocation of the piston in each mold cavity is regulated by a control means which includes means for limiting the free upward movement of the piston until the cavity opening is fully aligned with a feed opening in the feed spout assembly.

This is a continuation of application Ser. No. 959,384, filed Nov. 9,1978 now U.S. Pat. No. 4,193,167.

This invention relates to improvements in an apparatus for formingpatties from an agglomerable edible material such as meat. Moreparticularly, the invention relates to improvements in a patty-formingapparatus of the general type described in the Orlowski U.S. Pat. No.4,065,241.

BACKGROUND OF THE INVENTION

Meat for use in making hamburger patties or the like is ordinarilyprovided in the form of large frozen blocks. In the prior art machinesand methods for forming patties the frozen blocks of meat are broken upinto smaller pieces which are then cut into flakes and warmed to 30° F.or higher before being introduced into the supply hopper of thepatty-forming machine. The warming of the frozen meat flakes has beenconsidered necessary to render the meat sufficiently soft or plastic tobe handled by the machine and formed into cohesive patties.

A particularly advantageous patty-forming machine is described in theOrlowski U.S. Pat. No. 4,065,241 and comprises a power driven turretmounted for rotation on a vertical axis with a plurality ofpatty-forming molds being provided on the turret. Each mold comprises abottom opening cavity in the turret and a piston mounted forreciprocation in the cavity in timed relation to the rotation of theturret. As the turret rotates, each mold is moved past a stationaryfeeding mechanism where meat from a supply source is forced into themold cavity as the piston moves upwardly in the cavity. As the turretcontinues its rotation, the piston is moved downwardly in the cavity andthe formed patty is ejected from the mold at a location substantially180° away from the feeding mechanism. A patty separating device in theform of a continuous moving cut-off band is positioned at this locationand effects separation of the formed patty from the bottom surface ofthe piston. The separated patty is then deposited on a moving conveyor.

In the aforementioned Orlowski U.S. Pat. No. 4,065,241 the feedingmechanism comprises a housing containing a pair of augers which feed themeat upwardly through an opening in a horizontal retaining plate whichcommunicates with each mold opening successively as the turret rotates.The retaining plate is rigidly mounted on the frame of the apparatus andis positioned such that the bottom surface of the turret sweeps acrossthe top surface of the retaining plate.

The Partos U.S. Pat. No. 3,633,245 describes a machine for formingmeatballs or the like which also has a rotary turret with bottom openingmold cavities and reciprocable pistons and a feeding mechanism forforcing meat upwardly into the mold cavities. In this machine thefeeding mechanism has a discharge head with an upper plate which engagesthe lower surface of the rotating turret. The upper plate of thedischarge head is forced upwardly against the lower surface of theturret by a series of levelling studs coacting between the dischargehead and the supporting framework of the machine.

SUMMARY OF THE INVENTION

The present invention is directed to improvements in a patty-formingapparatus of the rotating turret type described above which makes itpossible to use frozen flake cut meat without the necessity of warmingthe meat to render it soft and plastic. As a result of the highoperating speed of the machine, typically 400-450 patties per minute,the formed patties are essentially in the frozen state, which is asignificant advantage not heretofore obtainable in machines of thistype. The use of frozen meat, e.g. at a temperature of about 26° F. orlower, requires higher feed pressures than heretofore employed, and thepresent invention is directed to improved means for effecting a highpressure seal between the rotating turret and the stationary feedmechanism. The invention is also directed to certain improvements in thecontinuous moving cut-off band, which improvements are particularlyadvantageous when the apparatus is being used to process frozen meat.

Accordingly, a principal object of the present invention is to providean improved apparatus for forming patties at high speed from anagglomerable edible material, particularly frozen flake cut meat.

A further object of the invention is to provide, in an apparatus of theforegoing type, improved means for providing an effective seal betweenthe feeding mechanism and the rotating turret under the relatively highfeed pressure required as a result of the use of frozen meat.

Another object of the invention is to provide, in an apparatus of theforegoing type, an improved separating means for effecting separation ofthe formed patties from the patty-forming mechanism.

Briefly described, the improved sealing means of the present inventioncomprises a vertically movable support for a feed spout assembly havinga seal plate, and retractable fluid pressure applying means acting onthe support to urge the seal plate under balanced pressure into sealingengagement with the bottom surface of the rotating turret. The uppersurface of the seal plate is provided with a layer of sealing materialhaving a low coefficient of friction, preferably an ultra high densitypolyethylene material. The feed spout assembly is detachably mounted onthe support to permit easy removal of the feed spout assembly, forcleaning or the like, upon retraction of the fluid pressure applyingmeans. The fluid pressure applying means is preferably an air inflatableand deflatable flexible bellows device commonly referred to as apneumatic actuator or air bag.

In the present invention the continuous moving cut-off band, whichserves to separate a formed patty from the bottom surface of a piston,is disposed at a slight inclination across its width as it enters theinterface between the piston surface and the patty, and the leadingcorner of the piston is chamfered to facilitate entry of the leadingedge of the band into the interface. The cut-off band is looped betweena driving pulley and an idler pulley, and the pulleys have adjustablepivotable mountings for providing the desired degree of inclination ofthe band. In addition, a yieldable spring tensioned mounting is alsoprovided for the idler pulley. To avoid undesirable accumulation of themeat or other edible material on the band, stationary scrapers aremounted so as to clean the outer surface of the band and one of thepulleys, and spray nozzles are arranged to direct sprays of cleaningliquid against the band and the pulley to wash away the scrapings.

Other features and advantages of the invention will be seen from thesubsequent detailed description of the invention in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the improvedpatty-forming apparatus of the present invention, with portions of thestructure being omitted for clarity;

FIG. 2 is an enlarged vertical sectional view taken substantially on theline 2--2 of FIG. 1;

FIG. 3 is an enlarged vertical sectional view taken substantially on theline 3--3 of FIG. 1;

FIG. 4 is an enlarged fragmentary sectional view showing a detail of thestructure illustrated in FIG. 3;

FIG. 5 is an enlarged plan view as seen along the line 5--5 of FIG. 2;

FIG. 6 is a transverse sectional view as seen along the line 6--6 ofFIG. 5;

FIG. 7 is an enlarged side elevational view as seen substantially alongthe line 7--7 of FIG. 1; and

FIG. 8 is a fragmentary plan view as seen along the line 8--8 of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a preferred embodiment of the improvedpatty-forming apparatus of the present invention is designated generallyat 10, with portions of the structure being omitted for clarity.

The basic elements of the apparatus (i.e. a rotating turret withcavities, reciprocable pistons in the cavities, a feeding station at oneside of the turret, and a patty-discharge and separating station at theopposite side of the turret) are shown in the prior Orlowski U.S. Pat.Nos. 3,982,035 and 4,065,241 which are incorporated herein by reference.

The apparatus includes an enclosed frame 11 upon which is mounted asuitable drive mechanism (not shown) for driving the various portions ofthe apparatus in timed relation. A vertical drive shaft 12 connected tothe drive mechanism is supported on the frame 11 and carries at itsupper end portion a disk-shaped turret or cavity plate 14. In FIG. 1 therespective rotary positions of the turret 14 are designated by theletters A through F.

Referring particularly to FIGS. 2 and 3, the rotatable turret 14 has aplurality of vertically disposed circular openings 18 which arecircumferentially spaced around the turret. An upright tubular cavitybody member 19 extends into each opening 18 with a shoulder portion 21seated against the upper flat surface of the turret 14. The innercylindrical side wall 22 of the member 19 provides a cylindrical moldcavity, and each mold cavity has a cylindrical piston 23 disposedtherein for vertical reciprocation. The flat bottom surface, designatedat 24, of the piston 23 together with the cavity side wall 22 define thepatty-forming mold. Each piston 23 is affixed to the lower end of anupright piston rod 27 which is reciprocably supported in a tubularbearing portion 28 of a cavity cap member 29 which is seated against theupper end portion of the cavity body member 19. A cam follower holder 32is rigidly affixed to the piston rod 27 above the upper end of thebearing portion 28 and carries a cam follower or side roller 33 whichprojects laterally from the piston rod 27. A U-shaped yoke or holder 38is secured to the upper end of the piston rod 27 and has mounted thereinanother cam follower or top roller 39 in vertical alignment with thepiston rod 27. As seen in FIG. 2, the outer surface of the roller 39 isrecessed slightly below the upper end surfaces 41 of the holder 38. Ashereinafter described, the rollers 33 and 39 coact with suitablypositioned cam tracks and a strike plate which comprise a control meansfor regulating reciprocation of the piston 23 in the cavity 22.

A feeding means comprising a feed device in a housing 42 is mounted onthe frame 11 at a feed station (position A in FIG. 1) located at oneside of the turret 14 for feeding the meat or other agglomerable ediblematerial from a supply hopper 43 upwardly into each mold cavity 22successively during rotation of the turret 14. Although any suitablefeed device may be used, an auger type device known in the trade as aMoineau pump is preferred, as more fully described in the aforementionedOrlowski U.S. Pat. No. 4,065,241. The feed device communicates with aninfeed elbow, shown fragmentarily at 44 in FIG. 2, which has adetachable connection with a feed spout assembly, designated generallyat 45, which is positioned below the rotating turret 14. A pattyseparating means, indicated generally at 48, is also mounted on theframe 11 at a discharge station (position D in FIG. 1) located adjacentthe turret 14 and approximately 180° away from the feed station. Asdescribed in more detail below, the patty separating means 48 comprisesa continuous moving cut-off band disposed below the turret 14 in thepath of rotation of the mold cavities.

As previously explained, the present invention pertains to an improvedmeans for effecting a seal between the feed spout assembly 45 and therotating turret 14 which permits feeding of agglomerable ediblematerial, particularly frozen flake cut meat, under substantial pressurefrom the feed device. Referring particularly to FIGS. 2, 5 and 6, thefeed spout assembly 45 comprises an elongated generally arcuate sealplate 52 having on its upper surface a layer 53 of a suitableself-lubricating sealing material having a low coefficient of friction.The sealing material must be adapted to withstand the relatively highforces encountered when pressed against the bottom surface of therapidly rotating turret 14 so that there is no detrimental wear orattrition of the layer 53 and no objectionable residue is deposited onthe bottom surface of the turret 14. In addition, the sealing materialmust be one that is non-toxic and is approved by the regulatoryauthorities for use in a food processing environment. The preferredself-lubricating sealing material which meets these multiplerequirements is an ultrahigh molecular weight, high density polymericresin, e.g. the polyethylene resin offered by Hercules, Inc. under thetrademark "1900 UHMW Polymer" and having a molecular weight rangebetween 2 and 6 million.

The seal plate 52 and the layer 53 have a centrally located feed opening54 which has an irregular and generally semi-elliptical configuration.An inlet means for the edible material is affixed to the bottom side ofthe plate 52 and comprises a shallow dish-shaped housing 57 having anupstanding peripheral side wall 58 and a bottom wall 59. The upper edge61 of the side wall 58 engages the bottom surface of the seal plate 52,and the bottom wall 59 is spaced below the seal plate 52 to define anenlarged feed chamber 62 surrounding the feed opening 54. A tubularinlet stub 63 extends downwardly from a circular opening 64 in thebottom wall 59, and a removable clamp 65 provides a detachableconnection between the inlet stub 63 and the infeed elbow 44.

The seal plate 52 has a pair of depending mounting members in the formof mounting posts 66 rigidly affixed at the bottom side of the sealplate 52 in spaced relation at opposite sides of the feed opening 54.The mounting posts 66 are notched or recessed, as at 67, to receive thehousing 57 and are also provided with axially extending sockets 68 intheir lower ends for receiving support members, as described below. Aknife blade 69 is detachably secured to the inside of the side wall 58of the housing 57 by means of a screw 71 extending through a mountingportion 72, and the blade 69 is positioned so that an elongated knifeedge portion 73 is in operating alignment with the upper surface of theseal plate layer 53 and extends transversely across the trailing edge ofthe feed opening 54 as the mold cavities are rotated past the feed spoutassembly 45.

In accordance with the present invention, the improved seal meansincludes vertically movable support means for supporting the feed spoutassembly 45 below the rotating turret 14 at the feed station. As seen inFIG. 2, the support means comprises a pair of spaced upright thrust rodsor posts 76 having annular retaining shoulders 77. The upper ends of thesupport posts 76 are removably received in the sockets 68 of themounting posts 66 with the shoulders 77 abutting the ends of themounting posts 66. The support posts 76 are vertically slidable in guidemeans comprising a pair of upright tubular bearing members 78 which arerigidly affixed to an apertured horizontal platform 79 constituting partof the frame 11. The lower ends of the support posts 76 projectdownwardly through enlarged apertures 81 in the platform 79 and arerigidly interconnected by a transverse connecting structure 82 so thatthe support posts 76 and the connecting structure 82 are movable as aunit. A retaining means is rigidly secured to the bottom of the platform79 and comprises a U-shaped cradle structure, indicated generally at 83,having depending leg portions 84 secured at their upper ends to theplatform 79 and a transverse portion 86 rigidly interconnecting thelower ends of the leg portions 84 and extending in parallel spacedrelation below the transverse connecting structure 82 of the movablesupport means for the feed spout assembly 45.

A fluid pressure applying means 87 is interposed in operative relationbetween the transverse connecting structure 82 and the transverseportion 86 of the cradle structure 83 for transmitting a balanced upwardpressure against the seal plate 52 and thereby urging the surface 53 ofthe seal plate 52 into sealing engagement with the bottom surface of therotating turret 14. As shown in FIG. 2, the preferred fluid pressureapplying means is a flat generally disk-shaped pneumatic bellows deviceknown in the trade as an actuator or air bag. The device comprises aninflatable and deflatable flexible wall cylinder 88 enclosed between apair of circular metal end plates 89 and 91 having a crimped beadconnection to the bellows 88. The bellows 88 is formed from a heavy dutyflexible material such as nylon reinforcing cords encased in neoprenerubber. An air inlet (not shown) is provided in the bottom end plate 91and is connected to a source of pressurized air with suitable controlmeans for inflating and deflating the device as desired. By way ofexample, the actuators or air bags offered by Firestone IndustrialProducts Company under the trademark "Airstroke" are particularly usefulfor the purposes of the present invention.

A pneumatic actuator or air bag of the type shown in FIG. 2 is a highlyadvantageous means of applying effective sealing pressure against thefeed spout assembly 45 because of its compact size and configurationwhich enable it to meet the severe space limitations of thepatty-forming apparatus. Since the device is hermetically sealed, italso affords important advantages from a sanitary viewpoint as requiredin food processing equipment. Furthermore, the device makes it possibleto apply a controlled balanced pressure against the movable support forthe feed spout assembly so that the elongated arcuate feed plate 52 ispressed against the bottom surface of the rotating turret 14 in auniform manner to insure an effective seal over the entire contact areabetween the seal plate and the turret. Another important advantage ofthe device is that it is readily deflatable to permit the feed spoutassembly 45 to be removed easily for cleaning and also for maintenance,e.g. replacement or repair of the knife blade 69. Thus, upon detachmentof the clamp 65, the infeed elbow 44 can be swung away from the inletstub 63 and the bellows 88 can then be deflated permitting the movablesupport 76-82 to drop downwardly a sufficient distance so that the feedspout assembly 45 can be lifted off of the support posts 76.

The improved patty separating means 48 of the present invention, as bestseen in FIGS. 3, 4, 7 and 8 in conjunction with FIG. 1, comprises acontinuous moving narrow cut-off band 96 which is looped around a drivepulley 97 and an idler pulley 98 so that the upper operating bandportion 96' is positioned in the path of rotation of the turret 14 foreffecting separation of a formed patty. The pulleys 97 and 98 arecircumferentially grooved to receive the band 96, and the pulley 97 hasa drive connection 99 with the drive mechanism of the apparatus formoving the band 96 in timed relation to the rotation of the turret 14.Preferably, the speed of the moving band 96 is such that a clean sectionof band is presented as each successive mold cavity moves into pattyseparating position.

As hereinafter described, when a mold cavity 22 reaches the cavitydischarge and separating station, as shown at position D in FIG. 1, andin more detail in FIG. 3, the piston 23 is in its lowermost position andprojects slightly below the bottom surface of the turret 14 for fullydisplacing a formed patty 100 from the mold cavity 22. However, becauseof the nature of the patty material, particularly in the case of frozenmeat, the formed patty adheres to the bottom surface 24 of the pistonand must be positively separated therefrom by the cut-off band 96. Theelevation of the cut-off band is coordinated with the lowermost positionof piston 23 so that the operating band portion 96' enters the interfacebetween the piston surface 24 and the patty 100. The separated pattythen falls onto a moving conveyor 101.

In accordance with the present invention, the band 96 is mounted so thatthe band portion 96' is disposed at a predetermined slight inclinationfrom the horizontal across its width. This feature of the invention isshown on an exaggerated scale for clarity in FIG. 4 from which it isseen that the leading edge 102 of the band portion 96' as the bandenters the interface between the piston surface 24 and the patty 100 isslightly elevated relative to the trailing edge 103 of the band. Statedmore generally, the inclination is such that the leading edge 102 iscloser to the piston surface 24 than the trailing edge 103. It has beenfound that the preferred inclination is such that the distance "d"between the parallel planes of the respective edges is about 0.002 inchfor each 1/8 inch of band width. The inclination of the band portion 96'provides more effective separation of the patty 100 from the pistonsurface 24 and also functions to displace the separated patty from thepiston surface so as to avoid the tendency of the patty to re-adhereitself to the piston surface at the high speed of rotation of theturret. As also seen in exaggerated form in FIG. 4, the leading corneredge of the piston 23 as it moves past the band portion 96' is beveledor chamfered, as at 104, in order to guide and facilitate entry of theband portion 96' into the interface between the piston surface 24 andthe patty 100. The chamfered corner 104 also tends to cam the bandportion 96' downwardly, thereby avoiding interfering engagement of theband with the end of the piston and possible band breakage in the eventthat the leading edge 102 of the band is not effectively aligned withthe interface.

The desired inclination of the band portion 96' can be provided by anysuitable means, e.g. by auxiliary idler rollers mounted on suitablyinclined axes and engaging the band portion 96'. However, in theillustrated embodiment of the invention the desired inclination isobtained by means of adjustable supports for the pulleys 97 and 98 suchthat the axes of the pulleys can be tilted to provide the desiredinclination of the band. This feature is shown in FIGS. 3 and 7, theinclined relationship of the parts in FIG. 3 being exaggerated somewhatfor clarity.

The support for the driven pulley 97 comprises a bracket assemblyincluding an adjustable angle member 106 having leg portions 107 and108. The pulley 97 is rotatably supported on the leg portion 107, andthe leg portion 108 is adjustably secured to a fixed upright supportplate 109 extending upwardly from a base 110 secured to a platform 111constituting part of the frame 11. The adjustable connection between theleg portion 108 and the fixed support plate 109 is provided by means ofa pair of bolts 112 and 113, the upper bolt 112 extending through avertical slot 114 in the support plate 109 and an aperture 116 in theleg portion 108, and the lower bolt 113 extending through a verticalslot 117 in the support plate 109 and a horizontally disposed slot 118in the leg portion 108. Thus, the slots 114 and 117 permit verticaladjustment of the angle member 106 for vertically aligning the bandportion 96' with the piston-patty interface, and the slot 118 permitsslight pivotal movement of the angle member 106 about the bolt 112 as apivot axis, whereby to impart the desired inclination to the axis of thepulley 97.

The idler pulley 98 is rotatably supported by another bracket assemblyincluding a member 119 which is yieldably connected by pivot member 121to the upper end of the leg portion 122 of an adjustable angle member123. The other leg portion 124 of the angle member 123 is connected bymeans of bolts 126 and 127 to an upright support plate 128 fixed to abase 129 which is in turn mounted on the platform 111. The leg portion124 and the plate 128 have an arrangement of slots and apertures similarto that provided in the bracket assembly for the pulley 97 in order topermit coordinated adjustment of the inclination of the axes of thepulleys 97 and 98.

A tension spring 130 has one end connected to a mounting screw 131extending from the member 119 above the pivot 121 and its other endconnected to a mounting block 132 secured to the upper end of a fixedsupport 133 carried by the base 129. Thus, the band 96 is yieldablytensioned between the pulleys 97 and 98 by the spring 130 acting on thepivotally mounted support 119 for the idler pulley 98. In the event ofbreakage of the band 96, a new band can be installed easily and quicklyby disconnecting the spring 130, looping the new band around the pulleys97 and 98, and reconnecting the tension spring 130. Furthermore, in theevent of build-up of food or other extraneous material in the grooves ofthe pulleys, the spring tensioned mounting for the idler pulley 98provides automatic compensation for any increased tension in the band96. In addition, if there is unintentional misalignment of the band withthe piston-patty interface, the yieldable mounting of the idler pulley98 may avoid band breakage if the band is forcibly engaged by theprojecting end of the piston.

A further feature of the present invention comprises an improved meansfor cleaning the band and one of the pulleys, as shown in FIGS. 7 and 8.As previously mentioned, the pulleys 97 and 98 have circumferentialgrooves indicated at 136 and 137, respectively, which receive the band96. For optimum operation of the cut-off band it is important that theband be kept clean and free of accumulated meat or other edible materialwhich tends to adhere particularly to the outer surface of the bandportion 96' during its movement through the piston-patty interface. Inaccordance with the present invention, scraper means and liquid spraymeans are provided to clean the outer surface of the band portion 96'after it has moved away from a position closely adjacent the bottomsurface of the turret but before it returns to operating positionadjacent the turret surface. The scraper means also cleans the groove ofthe pulley around which the band portion 96' moves upon leaving thebottom surface of the turret.

An elongated horizontal support bracket 138 extends along one side ofthe drive pulley 97 at the lower portion thereof and is supported at oneend in cantilever fashion from the upper end of an adjustable anglemember 139 having leg portions 141 and 142. The leg portion 141 isadjustably mounted by means of bolts 143 and 144 on a fixed supportplate 146 extending upwardly from the base 110. The leg portion 141 andthe plate 146 are provided with the same general arrangement of slotsand apertures heretofore described in connection with the pulleys so asto permit pivotal adjustment of the bracket 138 in unison with thebracket assemblies for the pulleys 97 and 98. The bracket 138 has anupstanding outer end with an upwardly angled scraper blade 147adjustably mounted thereon by screws 148 so that the operating edge ofthe blade 147 is positioned at the outside of the pulley 97 where theband 96 is in contact with the pulley. The blade edge extends into thegroove 136 of the pulley 97 and engages the outer surface of the band 96for cleaning the latter. A downwardly angled scraper blade 149 isadjustably mounted at the opposite end portion of the bracket 138 bymeans of screws 151 so that the operating edge of the blade ispositioned at the inside of the pulley 97 where the band 96 is out ofcontact with the pulley. The blade edge extends into the groove 136 ofthe pulley 97 and engages the base of the groove for cleaning thelatter.

An upper liquid spray nozzle 152 is secured to the upper end of the legportion 107 of the angle member 106 and is disposed at a downward anglefor directing a spray of cleaning liquid around the scraper blade 147 soas to wash away the scrapings and provide a liquid coating on the outersurface of the band 96. Another liquid spray nozzle 153 is secured tothe bracket 138 adjacent the scraper blade 149 for directing a spray ofcleaning liquid into the groove 136 immediately below the scraper blade149 to wash away the scrapings. The cleaning liquid supplied to thespray nozzles 152 and 153 may conveniently be hot water or a hotvegetable oil or the like which is compatible with meat or the otheredible patty material and which is acceptable for food usage. Adownwardly inclined housing, shown fragmentarily at 154, is providedaround at least a portion of the pulley 97 and is suitably mounted onthe leg portion 107 of the bracket assembly for the pulley 97. Theliquid sprays from the nozzles 152 and 153 are directed into and areconfined by the walls of the housing 154 so as to collect the sprayliquid containing the scrapings and carry it away to waste or tofiltration for recycle to the spray nozzles.

A typical operating cycle of the apparatus will now be described withparticular reference to the mold positions designated at A-F in FIG. 1.During operation of the apparatus the reciprocation of the piston 23 isregulated in timed relation to the rotation of the turret 14 by suitablecontrol means, including a plurality of stationary cam trackscooperating with the rollers 33 and 39, so that the piston movesupwardly for filling the mold with edible material at the feedingstation when the bottom opening of the mold cavity is in communicationwith the feed opening 54 of the feed spout assembly in one rotaryposition of the turret 14, and the piston moves downwardly fordischarging a formed patty from the mold cavity at the discharge stationin another rotary position of the turret 14 which is remote from thefirst mentioned position.

The cam tracks are constructed and positioned so that when a mold cavity22 is completely aligned with the feed opening 54, as at position A ofFIG. 1 and as seen in detail in FIG. 2, the rollers 33 and 39 are fullydisengaged from the cam tracks and the piston 23 is free to moveupwardly under the feed pressure of the upwardly moving edible material,designated at 156 in FIG. 2. The upward movement of the piston 23continues until the upper end surfaces 41 of the yoke 38 abut against anadjustable upper strike plate 157 having a cushioned bump pad 158. Thepositive limitation on the upward stroke of the piston insures that thepatties are always of uniform size and weight. The strike plate 157 ismounted on the frame 11 above the turret 14 and is vertically adjustableby means of a pair of elongated threaded screws 159 engageable with ahand operated worm gear mechanism (not shown). Thus, the upward strokeof the piston 23 is adjustable to determine the size of the mold cavityand the formed patty, and it is an important advantage of the apparatusthat the size and weight of the patty can be accurately adjusted evenwhile the machine is in operation.

As the turret 14 rotates away from position A, in a counterclockwisedirection as viewed in FIG. 1, the underside of roller 33 is engaged bya flat portion of a first cam track, indicated schematically at 161 inFIG. 2, which holds the piston 23 in its uppermost position until themold cavity 22 has completely cleared the feed opening 54 of the feedspout assembly 45. During movement of the filled mold cavity 22 past thefeed opening 54, the knife edge 73 at the trailing edge of the feedopening 54 provides a clean cutting action to separate the portion ofedible material in the mold cavity 22 from the main bulk of the ediblematerial in the feed spout assembly 45. The knife edge 73 also functionsto sever any chunks or strings of meat, or other edible material, whichmay be at the bottom of the cavity 22, thereby insuring an acceptablenon-deformed bottom surface on the patty.

As the turret 14 continues to rotate to positions B and C of FIG. 1, theside roller 33 clears the first cam track portion 161, and thereafterthe top roller 39 is engaged by an inclined portion of a second camtrack (not shown) which fits between the sides of the U-shaped holder 38to engage the roller 39. The second cam track forces the piston 23downwardly in the mold cavity 22 until it reaches its lowermostposition, at position D of FIG. 1 and as seen in detail in FIG. 3. Thedownward limit of piston movement is reached when the holder 32 engagesthe upper end of the bearing portion 28. As previously described, whenthe piston 23 reaches this lowermost position, the lower end of thepiston projects slightly below the lower surface of the turret 14 andthe formed patty 100 is adhered to the bottom surface 24 of the piston.The piston 23 is retained in its lowermost position by engagement of thetop roller 39 with a flat portion of the second cam track, indicatedschematically at 162 in FIG. 3, until the mold has moved past the pattyseparating means 48 where, as previously described, the cut-off band 96passes through the interface between the piston surface 24 and theformed patty 100 and effects separation of the patty which falls ontothe conveyor 101.

During continued rotation of the turret 14 away from position D toapproximately position E, the top roller 39 clears the second cam trackportion 162, and thereafter the underside of roller 33 is engaged by aninclined portion of a third cam track (not shown) which lifts the piston23 slightly upwardly until the bottom surface 24 is in flush alignmentwith the bottom surface of the turret 14 preparatory to movement of themold cavity to the feed station at position A. Just prior to reachingthe feed station, e.g. at approximately position F, the side roller 33clears the third cam track aand at the same time the top roller 39engages a fourth cam track (not shown) which serves to limit upwardmovement of the piston 23 so that its bottom surface 24 is in flushalignment with the bottom surface of the turret 14 until the bottomopening of the mold cavity 22 is completely aligned with the feedopening 54. Thus, free upward movement of the piston 23 under the feedpressure of the meat or other edible material 156 cannot occur until thebottom opening of the mold cavity 22 is fully exposed to the feedopening 54 and the inlet chamber 62. When full alignment occurs, the toproller 39 disengages from the fourth cam track to allow free upwardmovement of the piston 23 as heretofore described.

As will be understood from the foregoing description, an improvedsealing means is provided by the movable support 76-82 for the feedspout assembly 45 and the air bag device 87 which urges the seal plate52 into sealing engagement with the bottom surface of the rotatingturret 14. Although the arcuate seal plate 52 has a spaced two-pointsupport on the posts 76, the arrangement is such that a uniform balancedpressure is exerted throughout the entire contact area between the sealplate and the turret. Typically the upper end plate 89 of the air bag 87has a diameter of about 10 inches and the air pressure in the air bag isfrom about 60 to about 100 psi so that the upward force imposed on themovable support 76-82 is in the range of 4700 to 7800 pounds. Thus, theseal between the seal plate surface material 53 and the bottom surfaceof the turret 14 is effected at relatively high pressures as required toprevent leakage between the seal plate and the turret when frozen flakecut meat is being supplied at a relatively high feed pressure from thefeed device. The use of ultra high density polyethylene, or equivalentmaterial, for the seal plate layer 53 permits an effective high pressureseal at the high rotary speed of the turret 14 without detrimentalerosion of the layer 53.

By means of the present invention, the frozen blade cut meat can beformed into patties without the necessity of warming the meat to 30° F.or higher, as was heretofore necessary. During the high pressure feedingof the frozen meat into the mold cavities the temperature of the meatmay increase enough to effect momentary or localized melting so as tofacilitate forming the meat into patties, but at the high productionspeed of the apparatus (e.g. 400 to 450 patties per minute for a sixcavity turret) the formed patties are still in substantially frozencondition so that refreezing is not required. The use of a transverselyinclined cut-off band, in the manner described, is also particularlyadvantageous when the apparatus is used with frozen meat because of thegreater tendency of the frozen meat patties to stick to the bottomsurfaces of the metal pistons. Furthermore, the scrapers and liquidspray nozzles described above also have special utility when formingpatties from frozen meat.

Although the invention has been described above with particularreference to an illustrated specific embodiment of the invention, it isto be understood that various modifications and equivalent structuresmay be resorted to without departing from the scope of the invention asdefined in the appended claims.

We claim:
 1. In the method of forming patties from a mass ofagglomerable edible material such as meat wherein said edible materialis fed upwardly under pressure from a feed means having a feed openinginto each of a plurality of upwardly extending cavities which are movedsuccessively into and out of communication with said feed opening, eachcavity having a piston reciprocably mounted therein and each pistonhaving a bottom surface cooperating with the cavity to define apatty-forming mold with a bottom opening, each piston being movableupwardly in its cavity for filling the mold with said edible materialwhen the bottom opening of the mold is in communication with said feedopening and the piston thereafter being movable downwardly fordischarging a formed patty from the cavity when the botton opening ofthe mold is out of communication with said feed opening;the improvementwhich comprises the steps of restraining upward mold filling movement ofeach piston in its cavity until the bottom opening of the cavity issubstantially completely aligned with and substantially fully exposed tosaid feed opening, and then freeing the piston for upward mold fillingmovement under the pressure of the edible material from the feed means.2. The method of claim 1 wherein said cavities are provided in a turretmounted for rotation on a vertical axis with said cavities extendingupwardly from a bottom surface of the turret, and the bottom surface ofeach piston is held in substantially flush alignment with the bottomsurface of said turret during said restraining step.
 3. In an apparatusfor forming patties from a mass of agglomerable edible material such asmeat; said apparatus includinga turret mounted for rotation on avertical axis and having a plurality of cavities extending upwardly fromthe bottom surface of the turret, each cavity having a pistonreciprocably mounted therein and each piston having a bottom surfacecooperating with the cavity to define a patty-forming mold with a bottomopening; feeding means cooperating with said turret for moving saidedible material under pressure from a supply source upwardly into eachmold successively during rotation of said turret relative to saidfeeding means; said feeding means having a feed opening, and the bottomopenings of said molds being adapted to be moved successively intocommunication with said feed opening during rotation of said turret;control means regulating the reciprocation of each piston in its cavityin timed relation to the rotation of said turret, whereby said pistonmoves upwardly for filling the mold with said edible material when thebottom opening of the mold is in communication with said feed opening ina first rotary position of said turret and whereby said piston movesdownwardly for discharging a formed patty from the cavity in a secondrotary position of said turret which is remote from said first rotaryposition; and means for separating a formed patty from the bottomsurface of said piston; the improvement wherein said control meanscomprises means for limiting the upward movement of said piston duringrotation of said turret from said second rotary position to said firstrotary position so that the bottom surface of the piston is insubstantially flush alignment with the bottom surface of said turretuntil the bottom opening of the cavity is substantially completelyaligned with and substantially fully exposed to said feed opening. 4.The apparatus of claim 3 wherein said means for limiting upward movementof said piston comprises cam means operatively coacting with the pistonto limit the extent of upward movement of the piston.
 5. The apparatusof claim 3 wherein said means for limiting upward movement of saidpiston comprises lift cam means operatively coacting with the piston formoving the piston upwardly during rotation of said turret away from saidsecond rotary position so that the bottom surface of the piston is insubstantially flush alignment with the bottom surface of said turret,and hold-down cam means thereafter operatively coacting with the pistonto retain said substantially flush alignment until said turret reachessaid first rotary position.
 6. The apparatus of claim 3 wherein saidcontrol means comprises abutment means operatively coacting with saidpiston for limiting the uppermost position of the piston during fillingof the mold at said first rotary position of said turret, first cammeans operatively coacting with said piston during continued rotation ofsaid turret to hold the piston in said uppermost position until thebottom opening of the mold clears said feed opening, second cam meansthereafter operatively coacting with said piston to move the pistondownwardly to its lowermost position in which the piston projectsslightly below the bottom surface of said turret for discharging theformed patty from the cavity at said second rotary position of saidturret and to retain the piston in said lowermost position until themold has moved past said patty-separating means, third cam meansthereafter operatively coacting with said piston to move the pistonupwardly during rotation of said turret away from said second rotaryposition until the bottom surface of the piston is in substantiallyflush alignment with the bottom surface of said turret, and fourth cammeans thereafter operatively coacting with said piston to limit upwardmovement of the piston and to retain said substantially flush alignmentuntil the bottom opening of the cavity is substantially completelyaligned with and substantially fully exposed to said feed opening atsaid first rotary position of said turret.
 7. The apparatus of claim 6wherein said piston has an upwardly extending piston rod, a holder atthe upper end of said piston rod, a top cam follower mounted on saidholder, a side cam follower mounted on said piston rod below said topcam follower, said abutment means is adapted to be engaged by saidholder, said side cam follower is adapted to be engaged by said firstcam means and by said third cam means, and said top cam follower isadapted to be engaged by said second cam means and by said fourth cammeans.
 8. The apparatus of claim 7 wherein said holder comprises a yokemember having spaced sides with upper end surfaces, said top camfollower comprises a top roller mounted in said yoke member between saidsides and in recessed relation below said upper end surfaces, said sidecam follower comprises a side roller projecting laterally from saidpiston rod, said first cam means and said third cam means comprise camtrack portions adapted to engage the underside of said side roller, andsaid second cam means and said fourth cam means comprise cam trackportions adapted to fit between said sides of said yoke member and toengage said top roller.